此代理转置源模型。 更多 …
New in version 5.13.
This model will make the rows of the source model become columns of the proxy model and vice-versa.
If the model is a tree, the parents will be transposed as well. For example, if an index in the source model had parent `index(2,0)`, it will have parent `index(0,2)` in the proxy.